Telephone system



' 1,505,715 M. LANGER TELEPHGNB SYSTEM Filed Aug. 29 1921 TI-Luau[Jrjifazc Lawyer ETZE."

Patented Aug l9, 1924.

n it E S new MAX LAn'eEn, or I-I-ERIVIMSKDORF, ,NnAn. BER-LIN, GERMANY,esszqrion TO AU'IQ'MATIC ELECTRIC COMPANY, or CHICAGO, ILLINOIS.

TELEPHONE s'Ysrnr/L I Application filed August 29, 1921. Serialnofee'seei (GRANTED UNDER THE mnvisimasor THE Aer or Manes i921;arsrA'r. L, 1213.

To all whom it may concern.

Be it known that I, MAX LANGE'R, a German citizen, and. a resident ofHerms dorf bei Berlin, Rodernstrasse 58, Germany, have inventedcertainnew; and useful 1m; provements in Telephone Systems (for which I havefiled application in Germany, application No. S 53922 VIII/21 datedAugust 10, 1920) of which the following is a specification. I

This invention relates in general to cir cuit arrangements for a twowire junctidn leading from an antomaticexchange to another exchange inwhich the testing for engagement is eifected over .only"one ofthe twowires. A feature of the arrangement is. that in addition to the blockingmeans at the outgoing end of the line, blocking means is also providedat" the other end under the control of connecting arrangements at thisend, which prevent the line being taken into use when the line is oiitof order orclosed for service. The blocking means at the incoming end ofthe line controls the testing arrangement at the other end over the testlead.

According to the present inventicn switching means are provided forconnect; ing' at the incoming end of the'tes't leader the trunk linepotential that difie'r's' from the blocking potential providedatthatendof the line, thereby setting in" action" the metering arrangement at theoutgoing end of the test lead. The trunlrlead iised for testing can thusbe used not only for controlling,

the testing arrangement by means of the blockingineans at the incomingend of the line, but also for additional switching processes, such asthe metering and release of a connection. Preferably the meterpotentia'l is connected to the te-st lead eitl ier 'after the connectionhas been completely set up or at the end of the conversation.

Furthermore the invention enables the selecting device to be releaseddirectly by the metering potential through the registering arrangementby means of one of the slow acting devices so that the releasing processis effected over the test lead in the direction from the outgoing end tothe incoming end.

The drawing shows diagrammatically an example of carrying out theinvention. The

contacts are given reference numbers and also small letters whichindicate the wind I ings. marked in capital letters by which they areoperated; thus the double wound relay A has armature contact 34.

il Vhen the receiver is lifted at the substation Ta the preselector isset in known manner on afree first selector I GW. The relays T and C areoperated from earthed battery contact '1, windings .I and II of therelay Tytest arm of the preselector VW, Winding I of theslow actingrelay C, oil normal contact Z0 earth. 1

The relay T short circuits at contact 2 the circuit of its highresistance winding I and switches the subscribers line through tothefirst selector I Gl/V at contacts 3 and 4-; At the first selector I GVVthe relay A is operated and closes a circuit from earthed battery,winding not the slow acting relay C, winding I ofthe slow acting relayV, contact s fi, 6 earth. The operation'of slow acting relay V Opens atcontacts 7 the cir cuit of the release magnet M. The contact 8 is closedbut the contact 9 controlled by relay A is opened hence the slow actingrelay 1V is not operated; At each train of number impulses the relay Vis' however eneigized and serves .then as a switching relay forthe firstselector IGlV, the second selecline VL, contacts '12, 1'3, winding I ofthe test arm of the first selector I GVV.

relay F x p II of the test relay I, contact 14".

winding windingl of the test relay P earth. The

test relay P is operated inthis circuit and short circuits at l5 itshigh resistance winding I, thereby the b lead of the trunk line isblocked at the outgoing end. The relay; Fis at first not operated owingto the differential effect of its windings II and III. 'Ihesubscriberslines are connected through at contact 16, 17, to the tree trunk line.Furthermore the circuit of the release 11mg net M is opened at contact18. At the first number impulse which operates the second selector IIGVV, the relay W is energized over contacts 8 and 9, while the winding Iof the relay E is energized in a circuit from earthed battery, relay Acontact 118, trunk lead a, winding I of the relay E, contacts 16, 33 and3 1, earth. Thereby the contacts 19 and 20 are closed and 21 opened. Therelay E locks itself in series with the windings II and III o't'therelay F. The b-lead of the trunk line is switched through at contact 20,thereby the test relay 1? is disconnected from the b-lead and thewindings II and III of the relay F are energized. finding I of the relayF no longer receives any current. By the energization of relay F, thecontact 22 is closed, and thereby the winding I of the relay E is shortcircuited. At the first lifting step of the second selector II GIV theoff normal contact 70 is operated, thereby the relay B, at the secondselector II GIV is energized in a circuit from earthedbattery,'resistance 0 contacts 31, 11, 17, 20,

b-lead of the trunk line, of? normal contact 70,, contact 23, windings Iand II of the relay B earth The relay B, at 23 removes the short circuitfrom the winding I of the relay C, and closes contact at. The relay Chowever, is not energized because it does not receive enough current.The second selector II GW sets itself on a free connector. Whenthesecond selector reaches the tree connector LIV a test circuit isclosed from earthed battery, relay (1,, winding I of the test relay Pcontact 25, winding II of the relay P earth.

-The test relay P is operated over this circuit and short circuits atcontact 26, its high resistance winding II. It therefore at 27 and 28switches the trunk leads a and I) through to the connector LIV and opensthe contact 29 in the circuit of the release magnet M By the operationof relay C the contact30 in the circuit of the release magnet M ot' theconnector LVV is: opened. During the transmission of number impulses forsetting the connector LIV, the slow acting relay IV is again energized,and the con-. tact 31 is thereby closed. The relay B at the connector isnow energized in the circuit from earthed battery, resistance o contacts31, 11., 17, 20, trunk lead Z), oil normal con tact 22,, windii'ig I ofthe relay (l, contact 28, relay 13,, earth. Likewise during the train ofimpulses for the connector IIW, the relay A, is energized in a circuitfrom earthed battery, relay A contacts 32, 27, trunk lead a, contacts22, 16, 33, 34, earth. lVhen the connection has been completed in knownmanner to the wanted subscriber and "when the latter has answered therelay Y through the winding I 01 the slow acting relay V, and thewinding II of the slow acting relay C. The relay C is so arranged thatit releases its armature a. little quicker than the slow acting relay V.Hence the slow acting relay V remains energized over:

its winding II and the (ale-ad of the trunk line VL in a circuit fromearthed battery, winding II of the slow acting relay V, contacts a0, 41,16, .22, trunk lead-a, contacts. 27, 37, resistance 0),, earth. Whenrelay 0 is deenergized it closes, the contact 10 and thereby connectsthe meter relay ZR to the b-lead. This meter relay ZR, however, is

only energized when the wanted subscriber.

hangs up his receiver, since the relay Y at the connector LVV is thendeenergized and closes contact 39 so that current passes from earthedbattery ZP, contacts 39, 38, 28, winding I of the relay C ofi' normalcontact 70 b-lead of the trunk line VL, contacts 20, 17, 10, meter relayZR, earth. Through the energization of the meter relay ZR- the contact42 is closed, and thereby the circuit of meter Z is closed, so that themetering is effected. Simultaneously with the energization of the meterrelay ZR, the contact 40 is opened and thereby the winding II of theslow acting relay V is deenergized.

The deenergization of the slow acting relay. V causes the contact 43tobe closed and thereby the winding II of the relay P is shortcircuited. The relay P releases its armature so that at contact 18 thefollowing release circuit is completed: earthed battery,

17 breaks the circuit of relay ZR which,

The energized release opens contact 42. magnet M, atcontact 4:6 opensthe circuit of the relay T at the pro-selector, so that the latter isalso rendered tree. The release of relay P causes the deenergization ofwindings II and III of the relay F and ot the winding II of the relay E.The relays E and F are so arranged that the relay E releases itsarmature quicker than the relay F, hence the winding II of the relay F sshort circuited at 21 after the relay E has been deenergized. Therelease of relay E also disconnects at 20 the b-lead of the trunk lineVL, so that an increasedcurmeans I *3 rent flows over the-winding I'IIofthe relay F and the relay C from earthed battery,

winding III of the relay F, contacts 21,44, 12, Oil normal contact 70,,winding I of the relay C windings I and II of the relay B earth SP. Therelay C is now energized. The operation of relays 'C, and B,

effect the short circuit of winding I of the relay P M in the followingcircuit: earthed battery, ofi normal contact release magnet M, contacts45, 29, earth. The second se lector II GNV is thereupon released.Furthermore the actuation of the off normal contacts 70,, causes thefree potential FP to be again connected to the trunk line; Subsequent tothe release of the relay P the relay G at the connector is deenergized.Thereby the contact 30 is closed and release magnet M is thereforeenergized in the circuit, earthed battery, off normal contact 70,,release magnet M contact 30, earth. Thus the connector LIV isdisconnected.

When the calling subscriber Ta' hangs up his receiver after the trunkline VL has been taken into use and before a train of impulses over thesecond selector II GVV has been transmitted, then the relay A at thefirst selector I GW is released and also the relay V because the earthpotential at the resistance a, is missing at the a-lead of the trunkline VL. The release of the slow acting relay V short circuits the relayP so that this releases its armatures. Hence the contacts 7 and 18 areclosed and thus the release magnet M of the first selector I GIV isconnected up. By the release of relay C its contact 10 connects up themeter relay ZR to the b-lead of the trunk line. However, the relay E isnot energized till the transmission of the first number impulse thatoperates the second selector I'I GIV and according to the abovementionedassumption has not yet been operated, therefore the b-lead of the trunkline VL has not yet been switched through at 20. Hence the meter relayZR receives no current from the meter battery ZP. The meter Z istherefore not operated although the disengaged potential FF is equal tothe meter potential ZP.

Having now described my invention What I consider to be new and desireto have protected by Letters Patent will be pointed out in the followingclaims.

lVhat I claim as my invention is:

1. In a telephone system, means including a train of automaticprogressively movable switches for connecting a calling and a calledline, means in the final switch for connecting a source of current toone of the talking conductors when the conversation is over with, saidmeans being responsive only to the replacement of the receiver on theThe relay P is therefore deenergized and thereby energizes the magnetcalled line, a mea-sured'service device for t-liecalling line, acontrolling relay for said device, and means I'BSPOHSIVQ only to thereplacement of the receiver on the calling line for connecting saidcontrolling relay to said talking conductor to render such relayresponsive to said current source.

2. In a telephone system, means includinga train of automatic;progressively mov able switches for connecting a calling and a calledline, means'in the final switch for connecting a source of current toone of the talking conductors Whenthe talking connection'i s broken,aineasured service device for the calling line, a. controlling relay forsaid device responsive to said current source, and releaseinechanisin'in said switches also responsive to said current source.

3. Ina telephone system, means including a train of automaticprogressively movable switches for connecting a calling and a calledline, means in the final switch for connecting a source of current toone of the talking conductors when the talking connection is broken, ameasured service device for the calling line, a relay in the first ofsaid switches, means in said switch controlled over circuits excludingthe succeeding switches for connecting said .relay to said talkingconductor to render the same responsive to said current source, and acircuit over which said relay controls the said meter.

4. In a telephone system, a two conductor trunk line connecting twoexchanges, a

meter controlling relay in the first exchange,

a two motion switch in the second exchange having a change over controlrelay, means in the first exchange for connecting a source of current toa conductor of said trunk during the setting upof a connection tooperate a two motion automatic switch in the second exchange having. achange over control re lay, means in the first exchange for connecting asource of current to a talking conduc tor of said. trunk during thesetting up of a connection to operate said change over control relay,and means in the second exchange controlled by the called subscriber forconnecting another source of current to said conductor for operatingsaid meter controlling relay,

6. In a telephone system, two exchanges, a two conductor trunk lineconnecting said exchanges, means including an automatic switch in eachexchange for setting up a talking connection over said trunk line, the

switch in the second exchange being conof said trunk line, a measuredservice device associated withthe calling line, and a controlling relayfor said device, controlled over said second conductor also.

7. In a telephone system, a trunk line connecting two exchanges,- anautomatic switch in the first exchange for seizing said trunk line, ameter control relay and a test relay in said switch, a source of currentin the second exchange for supplying current to said relays, said sourcebeing normally connected to a talking conductor of said trunk line,means for disconnecting said source after testing, and means for againconnecting it for metering, contacts normally connecting two exchanges,a meter controlling relay in the first exchange, a two motion switch inthe second exchange having a change over control relay, means in thefirst exchange for connecting a source of current to a conductor of saidtrunk during the setting up of a connection to operate said change overcontrol relay, and means in the second exchange for connecting anothersource of current to said conductor for operating said meter.controlling relay.

MAX LANGER.

